In a Wednesday meeting with Republican Rep. Mark Meadows of North Carolina, who leads the conservative House Freedom Caucus, White House budget director Mick Mulvaney agreed to revise the bill so that insurance companies would no longer be required to include a list of 10 benefits that Obamacare had compelled them to incorporate into their coverage.

President Trump also undertook a concerted effort to sell the bill on Wednesday. According to analysts, the president believes that a failure to repeal Obamacare would be a major political blow for his administration.

In order to win the vote of right-wing Rep. Steve King of Iowa, Trump publicly announced an amendment to the bill that would deregulate the health care industry. He obtained the support of Rep. Lou Barletta of Pennsylvania by addressing the congressman's concern about undocumented immigrants receiving health care tax credits. Trump also promised Rep. David McKinley of West Virginia, whose state includes a large number of miners, that he would try to protect health insurance and pension benefits for mine workers in order to win McKinley's vote.

These efforts may not be enough, as even staunch conservative donors with big pockets like the notorious Koch brothers have already promised to use their clout to protect Republican congressmen who ultimately vote against the repeal-and-replace bill.

Although Republicans had initially scheduled for a vote on the bill on Thursday, the last-minute nature of these revisions — along with the fact that Republicans had not yet selected a time for their Thursday vote — suggests that they may push back their vote in the hope of obtaining more support. Because Democrats are united in their opposition to the American Health Care Act, Republicans can only afford to lose 21 votes if they hope to pass the legislation. Yet while their new concession could attract conservative members who were opposed to the current draft of the bill (although even that remains unclear), it is likely to further alienate many of the moderate Republicans (like Rep. Charlie Dent of Pennsylvania) who are already opposed to it.

Matthew Rozsa

Matthew Rozsa is a breaking news writer for Salon. He holds an MA in History from Rutgers University-Newark and is ABD in his PhD program in History at Lehigh University. His work has appeared in Mic, Quartz and MSNBC.